James p



(No Model.)

J, F. MUNSIE. DUCT PCR ELECTRIC CCNDCCTCRS.

No. 426,205. PCtCntedApr.22,1890.

@14ml/who@ w: News uurs co., Hanru-mm, msnmmau, n. c.

UNITED STATES PATENT OFFICE.

JAMES E. MUNSIE, oE ERooKLYN, ASSIeNoR rro rrHoMAS L. coLES, or NEW Youn, N. Y.

DUCT FOR ELECTRIC CONDUCTORS.

SPECIFICATION forming part of Letters Patent No. 426,205, dated April 22, 1890.

Application filed January 17, 1890. Serial No. 337,249. (No model.)

To @ZZ whom t may concern: aluminum, and sulphate of zinc until the en Be it known that l, JAMES F. MUNSIE, a tire mass of pulp is completely impregnated British subject, residing at Brooklyn, in the with the said solution. The solution, after county of Kings and State of NewYork, have having acted upon the pulp, is then drained 5 invented certain new and useful Improveoff, and an equal part, by weight, of finely-pul- 5 5 ments in Duets or Conduits for Electrica-l verized lire-clay and an equal part, by weight, Conductors; and I do hereby declare the folof iinely-pulverized Portland cement, is added lowing to be a full, clear, and exa-ct descripto it, together with a sufficient quantity of tion of theinvention,such as will enable others white glue and silicate of soda to agglutinate 1o skilled in the art to which it appertains to and combine the whole. An intimate homo- 6o make and use the same. geneous mixture of these constituent parts is My invention relates to certain new and Secured by mechanical agitators or mixers. useful improvements in ducts or conduits for The mixture thus obtained may then be electrical conductors, and particularly to molded into the form of the pipe et and rings 15 means for constructing such ducts or conduits 5. The molded products are thereupon thor- 6 5 of highly-incombustible materials and in any oughly dried in a suitable oven, and while desired length without irregularities at theV still hot are immersed yin a hot bath of indiajoints. rubber or of lire-proof paint, (known com- ]n the accompanying drawings, Figure l merciallyasmineral paint.) The hot liquid 2o represents a central longitudinal section of is absorbed by the heated mass of the article 7o a portion of a duct or conduit embodying my plunged into it, and any existing porcs are invention, and Fig. 2 represents a cross-secfilled, thereby rendering the article thortion thereof, taken on the line 2 r?. of Fig. l. oughly waterproof. In order (when rubber Similar numerals of reference indicate simiis employed) to render said rubber non-ine 5 lar parts in both views. flammable, the article may thereafter be sub- 75 The duct or conduit is composed of two jected to the ordinary vulcanizing process. concentric pipes 3 4., having an intermediate The intervening space between the concenfilling of. pulverized mica, together with a tric pipes is closed at the ends by a sleeve., small quantity of silicate of soda and white serving at the same time to unite adjoining 3o glue or other non-infiammable agglutinating pipesections- The sleeve is provided at its So mixture or compound. central portion with an outer ange 6 and an Packing-rings 5 are nemployed in the coninner flange 7, which are respectively iush struction of the compound pipe for the purwith the outer wall of the pipe 3 and the inpose of compressing or packing down the fillner wall of the pipe e. The main body por- 35 ingin material, and are left in place, so as tions S of the sleeve extend into and close the S5 afterward to aid in preserving the proper sepaends of the intervening space between the ration between the two pipes and to strengthen concentric pipes, and a light coating of cemthe entire structure. ent 9 unites them to the pipe 3. About the The outer pipe 3 is made preferably of joint thus made is passed a coupling sleeve 4o glass or metal havingan incorrodible surface, or ring l0, held in place by screws 1l, which 9o so as to resist both decay and the attacks of pass through it and the outer pipe 3 and bear insects and rodents. The inner pipe et and against the innersleeve,assliown. Thecoupthe packing-rings 5 are made of a paper-pulp lingsleeve is preferably made of metal; but rendered non-inflammable and waterproof by the inner sleeve is formed of the same mate- 45 special treatment. rial as the pipe 4. 95

The Special treatment referred to is de The construction of joint shown and described in my application for Letters Patent, scribed is of especial importance in connec Serial No. 337,246, filed January 17, i890. It tion with ducts or conduits of the general consists in washing or boilinfr the paper-pulp character to which this invention is particu- 5o in a solution of common, salt, sulphate of larly applicable. Theinnersleeve serves not 10c only as a connection between the adjacent sections of the duct, but also serves to close the end of the intervening space during the manufacture of the pipe. The joint is Without internal projection Within the Walls of the pipe 4; and therefore said pipe when laid presents a smooth unbroken inner surface from end to end particularly appropriate to the insertion of electrical conductors and as Water-proof and non-inflammable at the joints as throughout its general extent.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

l. A duct or conduit tor electrical conduct ors, consisting of the concentric pipes 3 4, having an intervening filling, in combination with the sleeve 8, serving to ill the ends of the interveningT spaces in adjacent duct-sections and provided with an inner .fiange 7 and an outer iiange 6, substantially as and for the purposes described.

2. A duct or conduit for electrical cond uct,- ors, consisting of the concentric pipes 3 4, having an intervening iilling, in combination with a connecting-sleeve serving to iill the ends ot' the intervening space in adjacent duct-sections and cemented Within said ends, substantially as and for the purposes described.

3. A duct or conduit for electrical conductors, consisting of the concentric pipes 3 4,

having an intervening filling, in combination with a connecting-sleeve serving to fill the ends of the intervening space in adjacent duct-sections and cemented within said ends and provided with an inner ange 7 and an outer flange 6, substantially as and for the purposes described.

4. A du ct or conduit for electrical conductors, consisting of the concentric pipes 3 4, having an intervening filling, in combination with the sleeve 8, serving to ll the ends of the intervening spaces in adjacent duct-sections and providedwith an inner iiange 7 and an outerangc G, and an outer sleeve 10, connected to the outer pipe by screws ll, substantially as and for the purposes described.

In testimony whereof I affix my signature in presence ot two Witnesses.

JAMES F. MUNSIE. lVitnesses:

JOHN C. PENNIE, H. B. ZEVELY. 

